Sheet-fed intaglio rotary printing machine



H FED I NTING MACHINE l f f Patented July 6, 1937 i slmn'r-FlznV INTAGLIo ROTARY PmNTnvG MACHINE Paul Koch, Plauen, Germany AApplication January 7, 1935, Serial No. 780

In Germany January 8, 1934 1 claim. (ci. 10i- 151) This invention relates to a sheet-fed intaglio rotary printing press.

One of the objects of the invention is to avoid the waste of usable printing plate surface involved at printing presses of this type whereas heres tofore the printing cylinder, either if made half the size of the impression cylinder, h-ad to make two revolutions for each. sheet printed whereof one was idle, or it was only half covered with engraving to be reproduced, one half of its copper surface, if copper coated cylinders were used,

f being wasted or, if plate cylinders were used, not

being covered by the printing plate.

Another object of the invention is to ,nearly double the output of sheet-fed intaglio rotary printing presses without unduly increasing the printing and delivering speed which is limited by the requirements for suiiicient drying of the sheets, and without necessitating the use of double feeding and delivering stacks as heretoforev thought indispensable.

With these andl other objects and advantages in view my invention yconsists in the equipment of the machine not only with a feeding device of known type comprising two kinds of mechanically y cr air suction operated grippers the one of which being adapted to begin registration of the sheet at a moment when it is still over or under-lapped by the preceding sheet, the other being adapted o to engage the preceding registered sheet and to convey it toward the impression cylinder, but by dimensioning the impression cylinder -to which the sheets are fed so that the circumference thereof is less than one-fourth larger than the sheet length, the form cylinder being of the same size as the impression cylinder.

This construction aiords the added advantage that the printed sheet passes the press operator with the printed side up to facilitate supervision. For this purpose the sheet is supplied tothe printing mechanism on the side where the doctor is located on the form cylinder.

By way of example, one form of the invention is illustrated in the accompanying drawing.

The sheets are supplied from the pile I, by means of several types of mechanically or air suction operated grippers 1 and 8, to the im-V pression cylinder 2 which passes them through the printing mechanism and then to a chain conveyor which on the path 3 delivers themy to thepile 4 or to adrying device. y y The impression cylinder 2. isfdimensionedso that its'circumference is 'less than one-fourth of the length of the sheet larger than the latter. 5 The space thus remaining on the impression H cylinder between the first part of the rubber blanket and the end thereof need. onlyibe -largev enough to accommodate the grippers required for catching the sheets. The sheet feedingV de- 10 vice comprises, in known' manner, twofsets' of grippers 1 and 8,.' the gripper 1fpicking 'up the sheets from the pile land registering them for the second set of grippers which supplies them to the impression cylinder 2 insuch away that 15 f in the meantime the first set of grippers 1 can in the meantime liftv the next sheet from thepile.y

The form cylinder 5 is as large as the impression? i l cylinder 2, and the doctor-76' presses against the I. form cylinder 5 on the saine` sideon' which 2O the sheet feeding device is positioned. yThis makes it possible to pass the sheets around the impressionr cylinder 2 and .then yover the path 3, so that they may be examined by the machine opery ator. i

The reference character 9 indicates gripper rodsl 25 whichfeither are connected with the conveyorchain l0 or, on the path I5 from pulleyv lI-to `pulley,A i2.A Conveyor chain l0 is guidedwfby pul' leys I3 and I4. This conveying mechanism permits a certain amount of drying of the printed sheets before they are stacked on the pile 4.

A sheet-fed' intaglio rotary press .comprising an intaglio form cylinder, an impression-cylinder 35 having a set of grippers thereon, said cylinders f cooperating with each other and the diameters of Y the cylinders beingv approximately equal, a sheet feeding device disposed adjacent tothe impres' sion cylinder and feeding theretoone sheet at 40 each revolution of the cylinders; andthe entire f circumference of the vform cylinder being capable of printing except for the space required for said set of grippers'onthe impressionj cylinder, and a delivery device forstripping the sheets ofi the 45 impression cylinder and being disposed-in a position and direction over that in which the sheets are fed. I

PAUL KOCH, 

